My Goodness, I didn't know those cars used such a high voltage.
Since I mainly use a bicycle I recommend to leave the car at home on sunny days and take the bike. But I live in-town and rarely need to travel more than 3 miles one way, about 20 minutes. The rain, heat and cold can be inconvenient. Been riding for more than a year now, the positive benefits of health and weight should also be mentioned.
Having 2 batteries sounds appealing, but expensive and possibly difficult and time consuming to change. Combining 2 batteries with occasionally leaving the car on sunny days sounds like the ultimate in reliability.
Grid Tie isn't real for me, or cheating. I want to use the same electrons that I made, a closed system.